Plan to boost drilling on U.S. lands tilts to industry views. Questions about deposits' size, extraction costs and impact of environmental rules get short shrift.

The Bush administration is moving swiftly to expand oil and gas drilling on millions of acres of Western lands, opening up some of the nation's last unspoiled mountains, canyons and badlands from the Great Plains to the Pacific Ocean.

But the push for more energy sidesteps fundamental questions about how much fossil fuel lies beneath these public lands, how much can be extracted profitably and to what extent rules protecting wildlife and wilderness currently hamper energy production.

The Bush policy defers heavily to the industry's premise that large deposits of oil and natural gas were locked up by overzealous environmental protection during the Clinton administration.

Interviews with federal land managers and a review of government maps and geological reports by The Times, however, offer a contrasting picture. They show that oil and gas companies are leasing increasing amounts of public land every year, are able to drill in recently established national monuments and continue to operate even where they are subject to environmental regulations.

Those arguments were all but lost in an energy bill passed last week by the House of Representatives that embodies the White House philosophy. The trail that led to the bill shows how the industry shaped a policy that may overestimate the energy to be gained on the public domain while glossing over the environmental risks.

The Senate will take up the House bill in September, resuming a debate largely centered around proposed drilling on 2,000 acres of the Arctic National Wildlife Refuge in Alaska.

But the issue, in fact, is far larger.

At stake are conflicting visions for the management of more than 300 million acres of public land, the bulk of it in 11 Western states.

The Bush energy policy calls for increasing domestic drilling to meet rising demand for fossil fuels, maintaining that this can be done without damaging sensitive lands.

Conservationists and many scientists counter that the access roads, pipelines and processing plants that come with oil and gas fields irreversibly damage America's open space and wipe out wildlife habitat.

The House bill gives the administration leeway to discard "unwarranted denials and stays" of federal oil and gas leases nationwide, and allows Bush appointees to decide if the reasons for previous drilling bans "are still persuasive."

"That, in essence, means nothing is really off limits," said Johanna Wald, land program director for the Natural Resources Defense Council in San Francisco.

One regulation that could be reconsidered is a 1997 drilling ban in Montana's Lewis and Clark National Forest aimed at protecting vital habitat for grizzly bears.

Pointing out that the vast majority of federal lands in the West are already open to drilling, environmentalists have drawn lines around about 13.5 million acres they say should be left alone. Most of that acreage lies in the Rocky Mountain region, where the energy industry has shown a keen interest in natural gas deposits that are ideally positioned to supply the West Coast market.

The industry argues that land classified as open is far from it in reality.

"You might be able to lease it--the federal government is glad to take money--but you'll never get a permit to drill or to put in the roads to get in and drill," said John Guy, deputy executive director of the National Petroleum Council, an advisory panel to the Energy Department.

"What our group found was 40% was unavailable when you get down to it, because of administrative decisions or due to lease stipulations," he added.

The petroleum council is made up almost entirely of executives from the energy industry who are appointed by the secretary of energy. It is not allowed to lobby or act as a trade group.

But, in its advisory role to the Energy Department, the council drafted a 1999 natural gas report concluding that regulation was becoming a barrier to meeting rising demand.

Cheney Among Those Who Oversaw Report

Vice President Dick Cheney, then chief executive of Halliburton, an energy services conglomerate, was among the petroleum council members who oversaw that report.

Paid for by the council's corporate members, the study became a frequently cited source book for policy debate in the days leading up to House passage of the energy legislation, records show. Cheney coordinated the administration's energy plan.

Although Cheney did not ask the petroleum council to advise him, "individual members from individual companies did go over and talk with the Cheney folks," Guy said. "I know for a fact some of them used our reports."

The Bush policy adopts many of the report's conclusions, including assumptions about the amount of natural gas in the Rockies, how much is economical to extract and how much is impossible to access because of environmental restrictions.